GINNING PIMA COTTON IN AKIZONA 9 
ADJUSTMENT OF THE SEED GRID AND PUSHER BOARD 
The seed grid should be set as close to the moving knife as is 
necessary to keep the seed cotton from falling through with the 
ginned seed, and it should be low enough to expose all available roller 
space, giving the seed cotton the maximum degree of contact with 
the roller. Accumulation of seed on the grid in front of the roller 
undoubtedly reduces the efficiency of the gin, and there is a tendency 
on the part of ginners to pull back the grid in order that the seed 
may fall through easily. The danger is that many unginned seeds 
will fall through with the ginned seeds, causing a loss of fiber. 
The adjustment of the pusher board that moves back and forth 
on the grid is also very important. This board must come close 
enough to the roller to push the seed upon the moving knife in order 
that the latter may knock the seed back upon the fingers of the grid. 
If the pusher board is set too far away the seed will stay too long- 
in front of the roller space and interfere with more unginned cotton 
coming in contact with the roller. 
REMOVING THE COTTON FROM THE ROLLER 
The brush system used in the Sea Island districts to remove the 
cotton from the roller has not proved satisfactory in Arizona. How- 
ever, a new method has been devised and very satisfactory results 
obtained in the Salt River Valley by substituting for the brush a 
supplemental rapidly revolving roller with flexible flanges or flap- 
pers, called a flapper roller. (PL X.) This consists of a wooden 
roller 4 inches in diameter, provided with six flaps of -j^-inch pack- 
ing made of rubber or some other flexible material which will keep 
a smooth edge. These flaps protrude three-quarters of an inch from 
the face of the wooden roller. 
The roller is set back of the walrus-hide gin roller, on the same 
center, by means of special castings, and should be so adjusted that 
the edges of the flaps are as close to the gin roller as possible without 
touching it. The roller should be run at about 700 revolutions per 
minute, the same speed as the crank or moving knife, and can be 
driven by a belt from a pulley on one end of the crank. 
The flaps of the rapidly revolving roller lightly strike the sheet 
of cotton coming over the gin roller and lift it off, at the same time 
tending to straighten the fibers and throw out some of the dirt and 
foreign matter. 
An important feature is a provision for controlling the air current 
created by the flaps. If the air is not controlled it carries some of 
the cotton back under the rollers and may result in backlashing or 
in the loss of some of the cotton among the seed. The air-current 
breaker is a piece of sheet iron 8 inches wide and 40 inches long with 
a slight curve on one edge of the long side. It is fastened to the 
back of the gin stand and so adjusted that the curved edge will 
come between the two rollers and as close as possible to the gin 
roller without touching it. 
To further prevent the lint from being blown about by the air 
current a piece of sheet iron about 30 inches square should be fas- 
tened on each side of each gin stand. A screen cover placed across 
the upper edges of these side pieces will catch motes and other trash 
